5) Don't drive toward the sides of the road.
Okay, this isn't always possible. But here's the theory:
Roads are constructed so that they're highest in the middle. The difference may be slight, but it causes water to run off the center hump and drain toward the edges. If you're driving in the rain you want to avoid standing water, which means that you want to be where the water isn't -- and that's in the center of the road. No, the center won't be dry either, especially if it's still raining, but it's going to be the driest place around that isn't in somebody's garage.
4) Don't leave your headlights off (but don't make them too bright either).
When it's raining, what you need your headlights for, even in the daytime, is so that other people can see you.
But if headlights help you be seen, you don't want to unintentionally blind people with them either. Other drivers are already having enough trouble finding their way around. Don't dazzle them by turning on your high beams.
3) Don't drive if the windshield is so covered with rain that you can't see!
It doesn't matter if you know the road so well that you could drive it blindfolded while sound asleep, you still shouldn't drive it while there's enough water on the windshield to provide a home for goldfish.
There could be stopped cars in front of you that you can't see.
When visibility gets low, pull off the road as quickly as it's safe to do so.
2) Don't drive through a river.
If you see water flowing across the road from one side to the other and don't know how deep it is, don't try to drive across it! Let's say that again in case the rain was too loud for you to hear it the first time: Don't try to drive across it!
Better to wait out the storm and the rainwater than to lose your life -- and quite possibility the lives of those near and dear to you -- because you thought a little water couldn't hurt you.
And even if the water isn't moving, if the bottom isn't visible you don't know what's underneath it. There could be a pothole the size of a swimming pool. There could be broken glass or nails that fell off a truck. If you can't see the bottom, don't risk putting your tires on the submerged pavement -- or your life on the line. Either stop a safe distance from the water's edge or, if possible, find a way to drive around it.
1)Don't drive too fast for conditions!
When conditions are bad and roads are wet, speed limits are worthless. Drive well under them -- and the worse the conditions, the lower the speed you should drive.
Usually your tires can slice their way through the water in front of them and keep in contact with the surface of the road. But when the road is wet and you're going too fast, your car can actually begin to float on top of the water and the tire tread loses contact with the road surface. This is bad: You can no longer brake.
First off, don't panic (though, trust us, you'll be tempted to). Don't hit the brakes, because that just makes it worse. Let up on the accelerator so that any remaining traction can slow your speed. And drive straight. Don't try to turn. If the car is veering off in a direction you don't want to go, don't fight it; just follow your wheels. And as the car slows, suddenly (almost magically), you'll be back under control.